Cryptome.org has released WTC photos obtained by FOIA. This site has archived many other important 9/11-related documents, in addition to other material.
As the site says:
“Cryptome welcomes documents for publication that are prohibited by governments worldwide, in particular material on freedom of expression, privacy, cryptology, dual-use technologies, national security, intelligence, and secret governance — open, secret and classified documents — but not limited to those.”